Roadster Shop Chassis

From the moment 1959 Chevys hit showroom floors there was no mistaking them for anything else. Everything about their appearance was unique, particularly when viewed from the rear. We've always had a fondness for these cars, and as we couldn't think of anything cooler to drive on the AMSOIL/STREET RODDER Road Tour, we found a solid specimen and turned it over to Dean Livermore at Hot Rods by Dean to get it Road Tour ready.

While we admire the looks of our 1959, in this case beauty truly is only skin deep—underneath the stylish sheetmetal is a truly hideous chassis. First found under 1957 Cadillacs the X or cruciform frame was also found under 1958-64 Chevys. These frames had an hourglass shape and GM boasted that the design allowed the seating area to be lowered, which in turn made for a lower roofline. Although there was some truth to that claim, one of the lesser-known in-house arguments for the X-shape was cost effectiveness. The same basic frame could be used under a variety of cars, as simply changing the length of its centersection easily altered the wheelbase.

From a functional standpoint these frames had some significant shortcomings, not the least of which is the lack of torsional rigidity. While a floppy frame wasn't a big deal with the squishy suspension these cars came equipped with, but to accommodate the high-performance underpinnings a much more solid foundation would be required. We got the high-performance IFS and IRS we wanted and the new frame to hang them on from Roadster Shop.

The foundation for our Road Tour car is one of Roadster Shop's Fast Track perimeter frames, which they offer for 1958-64 Chevys. Each framerail is fabricated from four separate pieces of laser-cut 10-gauge cold-rolled steel welded together in a fixture. The completed frames are far stronger than the original design and require very minimal floorpan modifications to fit.

On each end of our new frame, Roadster Shop's Fast Track independent suspension will be found. As handling is a priority, allowances have been made to fit lots of rubber under the stock sheetmetal at all corners; there's room for 10-inch wheels with 285 tires up front and 12-inch wheels with 345 tires in the rear (we're only going to deal with the IRS this time; a detailed look at the IFS will follow).

Rather than just graft on an existing IRS, the Fast Track rear suspension was engineered by Roadster Shop for cars of this size and weight while complementing the tread width of the Fast Track IFS. The centersection is based on the venerable 9-inch Ford, heavy-duty CV joints, driveshafts are used, and the spindles are C6 Corvette.

For shocks and springs on both ends, Roadster Shop has teamed up with one of the foremost names in racing; all Fast Track suspension systems and complete chassis will now include Penske Racing Shocks as standard equipment. "Penske has long been the benchmark for high-performance shock absorbers. Instead of using a product that compares themselves to the best, we wanted to use the best in an effort to continue to bring our customers the highest quality and highest performance product out there," Phil Gerber, VP of Marketing for the Roadster Shop, says.

Our completed Roadster Shop Fast Track chassis was shipped to Hot Rods by Dean and they're already working fast and furiously to get the car ready for next summer. For information on how you can join in on the fun of the Road Tour, check the pages of STREET RODDER magazine, as well as streetrodder.com.

2/201. This is the original 1959 Chevy cruciform, or X-frame. Why it lacks resistance to twist and offers little protection in the event of side impact is easy to see.

3/202. Using a laser the full-length pieces of the framerails are cut from a sheet of 10-gauge cold rolled steel.

4/203. Zach Flores begins welding the ’rails together. By fabricating the frame out of separate pieces the complicated contours required to fit a perimeter frame under ’58-64 Chevys without extensive floor modifications can be created.

5/204. All the fabrication is done in a precision fixture. Here the inside boxing plate is being added to a framerail.

6/205. The stock body mount locations are used; additional mounts that align with reinforced sections of the body have been added as well.

7/206. During the assembly procedure dimensions are checked and rechecked to ensure accuracy.

8/207. With the ’rails fabricated and the body mounts in place, the center crossmember is installed. The perimeter frame offers more room for the engine, transmission, and exhaust as well as eliminating the need for a two-piece driveshaft.

9/208. The new Fast Track IRS was designed in-house at the Roadster Shop. Not only is it used for ’58-64 Chevys but it’s applicable to a variety of other cars as well.

10/209. A cradle system is used to mount the Fast Track IRS. Here it is being fitted to framerails.

11/2010. With the cradle in position assembly of the suspension can begin. Here the 9-inch housing is bolted in place.

12/2011. As with the front suspension, upper and lower control arms are used (here the uppers are being put in place).

13/2012. These are the stub axles and the retainer plates that hold them in the centersection.

14/2013. The stub axles are secured to the aluminum center housing by six bolts. The CV joints attach to the flanges on the stub axles.

15/2014. Half shafts are equipped with heavy-duty 930 and 934 constant velocity joints. Shafts are available to handle up to 1,400 hp.

16/2015. The spindles, hubs, and ball joints are C6 Corvette; Roadster Shop manufactures the control arms.

17/2016. All Fast Track chassis come standard with non-adjustable RS by Penske shocks that are valved for the specific application. We opted for the double-adjustable versions.

18/2017. All the components of the Fast Track IRS, including the coilovers, are easily accessible for adjustment or maintenance.